1. asc-abstracts.org http://www.asc-abstracts.org/
ASC 2015 Searchable Abstracts
9.01 Improving Predictive Value of Trauma Scoring Through Integration of ASA-PS with ISS
D. Stewart1, C. Janowak1, H. Jung1, A. Liepert1, A. O’Rourke1, S. Agarwal1 1University Of
Wisconsin,Surgery,Madison, WI, USA
Introduction: Many methods exist for predicting mortality among adult trauma patients; however, most systems
ignore patient co-morbidity, a significant predictor of outcome, in their calculations. The American Society of
Anesthesiologists Physical Status (ASA-PS), a well-validated and easy-to-use scale, is an assessment of pre-
operative status that has been shown to accurately predict post-operative mortality. Using the ASA-PS as a marker of
cumulative patient comorbidity severity we sought to test whether we would be able to improve the predictive power
of the Injury Severity Score (ISS), the most commonly utilized trauma grading system, with respect to mortality, major
complication, and discharge disposition.
Methods: A retrospective review of a prospectively collected and internally validated database at an academic Level
I trauma center was performed for consecutive adult admissions between 2009-2013. Abbreviated Injury Scale (AIS)
was measured by region (head/neck, face, thorax, abdomen, extremities, general) and severity of injury (1 to 5). ISS
was measured by summing the squares of the three most injured regions [(AIS1)2 + (AIS2)2 + (AIS3)2]. ASA-PS
scores were assigned based on patient comorbidities and then integrated with the traditional ISS in a variety of
permutations, including adjustments of ASA-PS for patient age >70 and using individual AIS components of ISS. We
assessed these various models for predictive ability with a primary outcome of mortality and secondary outcomes of
major complications as per National Trauma Data Bank (NTDB) definitions as well as discharge disposition using
receiver operating characteristic (ROC) analysis. These were compared with the ISS.
Results: All of the ISS/ASA-PS hybrid formulas outperformed ISS alone in predictive power for mortality, major
complication, and discharge disposition. The best overall permutation, (AIS1)2+(AIS2)2+(Age-Modified ASA-PS)2,
yielded an ROC of 0.888 for mortality as compared to ISS with an ROC=0.853 (p<0.001). Similar differences were
seen for discharge disposition (Hybrid ROC=0.743; ISS ROC=0.639, p<0.001) and major complication (Hybrid
ROC=0.761; ISS ROC=0.719, p<0.001).
Conclusion: Incorporating ASA-PS into calculations of trauma scoring is both simple and more predictive of mortality,
major complication, and discharge disposition than the traditional ISS metric. Replacing ISS with this new method,
which takes patient age and comorbid condition into account through adaptation of the ASA-PS improves
prognostication of outcomes and enables care providers to prioritize resources for injured patients.

2. Presentation Time: Tuesday, 7:30am - 9:30am
68.18 ASA-PS is Associated With Mortality Rate Among Adult Trauma Patients
D. Stewart1, C. Janowak1, A. Liepert1, A. O’Rourke1, H. Jung1, S. Agarwal1 1University Of
Wisconsin,Surgery,Madison, WI, USA
Introduction: American Society of Anesthesiologists-Physical Status (ASA-PS) classification assesses pre-
anesthesia surgical risk. Numerous studies correlate higher ASA-PS classification with increased perioperative
mortality. As the number of comorbidities in a traumatically injured patient is correlated to mortality rate, we evaluated
if ASA-PS was an indicator of mortality risk for adult trauma patients.
Methods: Our prospectively collected and internally validated database at an academic Level I trauma center was
retrospectively reviewed for adult patients for 2009-2013. ASA-PS scores were assigned based on patient
comorbidities. Three different methods were used to reflect a lack of concordance on the consideration of patient age
in establishing ASA-PS. In all three methods, NTDB-defined comorbidities were assigned an ASA-PS value and
summed for each risk level. Patients with no comorbidities were considered PS1, while PS2 consisted of those with a
single PS2 condition. Multiple PS2 conditions were considered multi-system disease, elevating a patient’s risk to
PS3. Presence of 3+ PS3 conditions led to a PS4 classification. We then evaluated mortality rates as a primary
outcome for each ASA-PS class using receiver operating characteristic (ROC) and Pearson Chi-Square analysis.
Discharge disposition and major complications were assessed as secondary outcomes.
Results: Model 1 (ASA), considered patient age >70 as a PS2 comorbidity, yielded an ROC of 0.619 for predicting
mortality. Model 2, not including age as a factor in ASA-PS (ASA–w/o Age), produced an ROC of 0.615. Model 3,
Age-Modified ASA (AM-ASA), produced an ROC of 0.648 (p<0.001). Cross-tabulation revealed mortality rates of

3. 2.4%, 2.4%, 4%, and 13.2%, for PS1, PS2, PS3, and PS4, respectively. ASA–w/o Age (2.4%, 2.7%, 3.9%, and
13.2%) showed a similar trend, as did AM-ASA (2.4%, 1.9%, 2.9%, 10.2%), albeit with a dip in mortality rate for PS2.
All three ASA models had two-sided p<0.001 under Pearson Chi-Square analysis of mortality rates. For discharge
disposition (ASA ROC=0.668; ASA–w/o Age ROC=0.650; AM-ASA ROC=0.693) and major complications (ASA
ROC=0.648; ASA–w/o Age ROC=0.653; AM-ASA ROC=0.641) all three models showed moderate predictive power.
Conclusion: ASA-PS classification models show an association between higher risk status and increasing mortality
rate. ASA-PS is moderately predictive of mortality, discharge disposition, and major complications per ROC analysis.
AM-ASA performed significantly better for mortality and discharge disposition, indicating that age can serve as an
adjustment to the codified system to improve accuracy in the trauma population.
Presentation Time: Thursday, 1:30pm - 3:30pm
39.07 The Surgical Apgar Score in Major Esophageal Surgery
C. F. Janowak2, L. Taylor2, J. Blasberg1, J. Maloney1, R. Macke1 1University Of Wisconsin,Division Of
Cardiothoracic Surgery,Madison, WI, USA 2University Of Wisconsin,Department Of Surgery,Madison, WI, USA
Introduction: Most postoperative assessments and triage decisions are based on subjective evaluation of a
patient’s risk factors and overall condition. The Surgical Apgar Score (SAS) is a validated prognostic tool used to
predict postoperative morbidity and mortality in a wide variety of surgical patients. The esophagectomy population is
a unique subset of surgical patients who are high risk for post-operative complication and disposition resources. An
objective prognostic metric is an appealing and efficient way to allocate limited care resources to the sickest of

4. postoperative patients. Although other more complex risk calculators have been developed, the SAS is a simple,
bedside usable, model that has been validated in a variety of surgical populations. We evaluated the reliability of the
SAS in a major esophageal surgery population.
Methods: A retrospective review of a prospectively collected and internally validated database of cardiothoracic
operations was performed for consecutive esophagectomies from 2009 to 2013. Basic demographics, comorbidities,
post-operative complications, and intraoperative variables were collected for all patients. The primary outcomes
studied were mortality and NSQIP-defined in-hospital major complication; secondary outcomes were prolonged length
of hospital stay (LOS) greater than 10 days and post-operative disposition. We used descriptive statistics, receiver
operating characteristics (ROC) and Pearson Chi-Square analysis to analyze primary and secondary outcome
prediction efficacy of SAS. Preoperative comorbid conditions were also analyzed for association with post-operative
outcomes prognostication using odds ratio (OR) analysis.
Results: A total of 172 consecutive esophageal resections over four years were reviewed. Overall mortality was 5
deaths (2.9%) with 4 occurring within 30 days of surgery, 1 after discharge within 30 days, and 1 after 90 days of
hospitalization. Overall SAS 9-10, n=16; SAS 7-8, n=113; SAS 5-6, n= 42; and SAS ≤ 4, n=1. Of these, 34.3% had a
major complication, 27.3% had a prolonged LOS, and 12.2% were discharged to a care facility other than home. No
significant correlation was demonstrated between complication, LOS, or discharge disposition and the SAS with
respective ROC of 0.44, 0.43, and 0.44. Of the preoperative comorbid conditions analyzed, only neoadjuvant
chemoradiation significantly increased the risk of any outcome, with an OR of 3.59 (95% CI 1.38-9.37, p < 0.01) risk
of discharge to care other than home.
Conclusion: The perioperative performance measure of the SAS does not appear to have a good ability to predict
major post-operative adverse outcomes in a major esophageal surgery population.

5. Presentation Time: Wednesday, 7:30am - 9:30am